Means for measuring rolling pressure



Jan. 9, 1968 R FLlNTH MEANS FOR MEASURING ROLLING PRESSURE Fild Oct. 28, 1963 Fig.2

INVENTOR K F04, 7e;

' frame/5 United States Patent 3,362,203 MEANS FOR MEASURING ROLLING PRESSURE Rune Flinth, Vasteras, Sweden, assignor to Allmiinna Svenska Elektriska Aktiebolaget, Vasteras, Sweden, 2 Swedish corporation Filed Oct. 28, 1963, Ser. No. 319,402 Claims priority, application Sweden, Nov. 9, 1962, 12,012/62 2 Claims. (CI. 7231) With that type of rolling mill where the rolling pressure is transmitted from working rollers with small diameter to support rollers which are situated in the rolling stand frame, great difliculties are experienced in measuring the rolling pressure with acceptable accuracy. The rolling pressure operating on the working rollers is distributed over intermediate rollers and support rollers to a fairly large surface of the rolling stand and operates in addition in dilferent directions on these by reason of the special positioning of the support rollers. Through the fact that the support rollers lie directly against the lining in the rolling stand the measuring means cannot be arranged in bearings in a known way. Neither is it possible to measure with desired accuracy the rolling pressure by measuring the stress in the rolling stand edge at the ends of the rollers, since such a measurement does not give information as to the magnitude of the power with which the rolling stand is actuated at a distance from the ends of the rollers.

The present invention relates to a means for measuring the rolling pressure in the above-mentioned type of rolling mills. The invention consists in that a number of holes are bored in the rolling stand and that one or more transducers are inserted in the holes, which give electrical outsignals, the magnitude of which depends on the magnitude of the mechanical stresses in the hole walls. With a specially suitable embodiment of the invention the holes are bored with their longitudinal direction parallel with the rollers in the rolling stand. The transducers used are suitably of that type which is described in United States Patent No. 3,184,963.

On the accompanying drawing FIGURE 1 shows a section in the rolling direction of one half of a rolling mill, where the invention is used, while FIGURE 2 is a section along the line 1-1 in FIGURE 1. FIGURE 3 shows in enlargement how a transducer is arranged in a hole.

The invention will now be further described in connection with the figures. The rolling material 1 lies against a lower Working roller 2 which is supported by a set of primary intermediate rollers 3. These are supported in their turn by a set of secondary intermediate rollers 4. Between the secondary intermediate rollers and the rolling stand 6 a set of support rollers is situated. The support rollers are positioned in the rolling stand by means of positioning means not shown here. In order to determine the pressure with which the support rollers activate the rolling stand four holes 7 are bored in the rolling stand. In the holes a suitable number of transducers 8 are inserted. The transducers are cylindrical and have a diameter which is slightly less than the diameter of the holes, so that by force fit or the like they can be inserted in the holes. The transducers consist of four magnetic cores 9, substantially rod-shaped and separated from each other, which are parallel with each other and with a diameter of the cylindrical transducer. The cores are thereby also parallel with a diameter of the hole. The cores are placed so that in a plane lying perpendicular to their longitudinal direction they lie in the corners of a quadrangle. Each core is provided with a winding 10 and the diagonally lying windings are connected together in pairs, the one pair being arranged to be connected to an alternating voltage source, while the other pair is intended to be connected to an alternating voltage sensing measuring device. These transducers sense the mechanical stresses in the edges of the holes and transmit an electric out-signal, the magnitude of which depends on said mechanical stresses. The out-signals from the transducers in a hole may be measured individually, so that information is obtained of the distribution of the rolling pressure along the longitudinal direction of the roller. All out-signals may also be added and thereby a measure of the total rolling pressure in the direction of the point of measurement is obtained. Both these measurements may be carried simultaneously so that with the help of the invention both the total rolling pressure may be measured and how this is distributed across the rolling direction.

The high rolling pressure operating on the working roller 2 will activate the rolling stand along a relatively large surface and the rolling pressure measured at a certain point in the rolling stand is consequently considerably lower than the pressure on the working roller. According to the invention by placing the transducer in holes parallel with the rollers an increase of the stress is however obtained, which is measured, because, if a round hole is situated perpendicular to the force direction in a material which is subjected to a mechanical force, the stress in the hole edge will as is known be three times as great as in the rest of the material and according to the invention the transducer measures the stress just at the hole edge which is evident from FIGURE 3. The measuring sensitivity thereby increases to a corresponding degree.

In the shown and described embodiment of the invention the holes 7 are situated where the mechanical stresses in the rolling stand are greatest. This is suitable in most cases, but not essential, but the holes could in principle be placed anywhere in the rolling stand. Neither is it essential that the holes are parallel with the rollers. It is also possible to bore the holes radially towards the support rollers, although such a solution of the measuring problem in most cases might be less successful. With the holes parallel to the rollers the transducers could be moved and placed anywhere along the longitudinal direction of the rollers, which is not possible'if the holes run radially inwards.

It is also not necessary to use this proposed type of transmitter. Ordinary strain gauge transducers, for example, may also be used, which in a known way are inserted in the holes and glued fast. The proposed transducer, however, in addition to better measuring properties, has the advantage that it can easily be brought to just that place where measuring is to be done and that it does not need to be glued or fixed in any other way to the hole walls.

The invention should thus not be considered as limited to the shown and described embodiment but it may be varied in many ways regarding the placing, direction and number of the holes as well as the choice of transducers and their placing in the holes.

I claim:

1. In a rolling mill having a stand and in which the rolling pressure is transmitted from a working roller with small diameter to support rollers situated in the stand, the stand having a plurality of holes therein, the longitudinal direction of said holes being substantially parallel with the axial direction of the rollers, means for measuring the rolling pressure comprising at least one transducer in each of said holes, said transducers giving electric out- 3 put signals the magnitude of which depends on the magnitude of the mechanical stresses in the Walls of said holes.

2. Means according to claim 1, several transducers being arranged in each of said holes, means to combine the output signals of said transducers to a total signal which corresponds to the total rolling pressure independent of how the rolling pressure is distributed along the length of the working roller.

References Cited UNITED STATES PATENTS Messinger 72-35 Sendzimir 72-245 Rendel 72-35 Dahle 72-35 RICHARD J. HERBST, Primary Examiner. 

1. IN A ROLLING MILL HAVING A STAND AND IN WHICH THE ROLLING PRESSURE IS TRANSMITTED FROM A WORKING ROLLER WITH SMALL DIAMETER TO SUPPORT ROLLERS SITUATED IN THE STAND, THE STAND HAVING A PLURALITY OF HOLES THEREIN, THE LONGITUDINAL DIRECTION OF SAID HOLES BEING SUBSTANTIALLY PARALLEL WITH THE AXIAL DIRECTION OF THE ROLLERS, MEANS FOR MEASURING THE ROLLING PRESSURE COMPRISING AT LEAST ONE TRANSDUCER IN EACH OF SAID HOLES, SAID TRANSDUCERS GIVING ELECTRIC OUTPUT SIGNALS THE MAGNITUDE OF WHICH DEPENDS ON THE MAG- 